1. Field of the Invention
This invention relates to a coupling construction of a shock absorber, and more particularly, to a construction for coupling a piston rod of the shock absorber with a car body.
2. Description of the Prior Art
Generally, when a piston rod of a shock absorber is coupled with a car body, a construction is employed in which a rubber bushing is interposed between the piston rod and the car body to prevent the car body from undergoing vibration transmitted from the shock absorber. However, the spring constant of the bushing is determined unconditionally and cannot be changed after the bushing, having predetermined hardness, profile and the like of rubber is incorporated in the car body.
An insulation construction was disclosed in the publication of the laying-open for public inspection of a Utility Model Application No. 76837/83, in which a first fluid chamber is defined by a bushing and a plate member, and a second fluid chamber is defined by the plate member and a diaphragm disposed on the opposite side of bushing to the plate member. Both fluid chambers are filled with fluid and communicate to each other through an orifice. According to this insulation construction, the vibrations transmitted from a shock absorber in the high and low frequency regions are reduced respectively by the bushing and a damping force produced when the fluid passes through the orifice.
In the construction disclosed in said publication the spring constant or damping coefficient of the bushing cannot be manually or automatically changed according to the running condition or taste.